Palin, 75, has given permission for the sketches to be reproduced and admitted the group often produced more material than was needed.

He said: "Sometimes you have things like that. I can't think why it wasn't used. The Holy Grail took shape gradually and at the beginning it had far more ideas in it than ended up on screen because you had to have a narrative. In the end the story of the knights was strong enough."

The material was donated to the British Library by Palin last year.

Michael Palin (Image: PA)

The archive spans the writer, actor, comedian and TV presenter's literary and creative life for more than 20 years, from 1965 to 1987.

On Monday, Cleese suggested the reason Monty Python's Flying Circus is no longer regularly shown on TV is because it's "too funny" compared to modern comedies.

Cleese revealed that his former Python colleague Michael Palin had previously told him their show had not been shown on the BBC for 17 years.

(Image: PA)

When asked why he thought it had been so long, Cleese replied: "I don't know maybe its too funny? It might not contrast well with some of the comedy they are doing now, you see what I mean?

"People might not laugh at modern comedy. Do you remember during (former BBC director-general) John Birt's reign they had a show called Men Behaving Badly?

"They had a poll to show the funniest comedies of all time, and that, which was made under John Birt's tutelage, was voted number one. Have you ever heard of it since?"